Hmmm. Now it's getting complicated.
Do you have any third party plugins installed?
Are all the fonts OK? You can check them using Fontbook.
Are you using a Font manager and is it compatible with Illustrator?
Since this started only recently: do you remember what you did on the computer before it got stuck? Installed anything?
Also: I assume you have rebooted the computer already?
I removed all plugins, after uninstalling the 2nd time - I also deleted all saved preferences. I did check my fonts, all good there. I generally use Adobe Fonts, so I'm not actually downloading or adding any fonts to Font Book.
The last time I used Ai was on 4/19 - seemed like it was something that happened quick. I tried older versions of Ai, checked updates that were ran on my iMac, but nothing.
I ended up contacting Adobe Support and they checked it out via remote support. After about 3-4 hours of them troubleshooting, turns out my user on my iMac is corrupted. I created a new user and everything is working fine.
Again, thanks for responding and providing some suggestions - much appreciated!